Web tension apparatus



Dec. 30, 1952 K. G. LAYCOCK 2,623,703

WEB TENSION APPARATUS Filed Feb. 13. 1948 2 Sl-IEETS,SHEET 1 TO PRESS INVEN TOR. KENNETH G. Lm cocx A T TORNE Y5.

WY M M Dec. 30, 1952 K. s. LAYCOCK WEB TENSION APPARATUS Filed Feb. 15, 1948 2 SHEETS-SHEET 2 INVENTOR. /(NNTH- G, Z/IYCOCK Patented Dec. 30, 1952 WEB TENSION APPARATUS Kenneth G. Laycock, Shavertown, Pa.

Application February 13, 1948, Serial No. 8,179

12 Claims.

The present invention relates to new and useful improvements in web tension apparatus particularly useful in controlling the feed of a paper web to a high speed rotary printing press.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate embodiments of the invention, and together with the description, serve to explain the principles of the invention.

The present invention has for its object the provision of a novel and improved web tension apparatus which will maintain a substantially constant tension on the web regardless of the diameter of the web roll. A further object of the invention is the provision of an improved Web tension apparatus by which a predetermined degree of tension on the web can be easily and accurately established and maintained substantially constant throughout the running of the roll. Still another object of the invention is the provision of a web tension apparatus for rotary printing presses which maintains a substantially constant degree of tension on the web at widely different speeds of operation.

f the drawings:

Figure 1 is a side elevation, partially schematic, showing a typical, preferred and illustrative embodiment of the present invention;

Figure 2 is an end elevation showinga portion of a modified embodiment of the present invention, the remainder of the parts being arranged and constructed as shown in Figure 1;

Figure 3 is a horizontal sectional view taken on the line 3-3 of Figure 2; and Figure 4 is a vertical section taken on the line 4-4 of Figure 3.

' Referring now in detail to the illustrative embodiment of the invention as shown in Figure 1 of the accompanying drawings, the invention is shown as applied to a conventional web roll support in which a Web roll I0 is rotatably mounted by means of a'shaft I l journalled in suitable bearings, not shown, the web roll being fast to a brake drum l2 having a deeply grooved surface in which are seatedbrake shoes I3 and l 4 each having an arcuate V-shaped face. The brake shoes are pivotally mounted on brake levers [5, I6 which levers are interconnected by a supporting link H to which they are pivoted at [8 and I9. Supporting link I! is mounted on a horizontal screw rod 20 which may be turned by hand wheel 2| and provides for the side leg or axle movement of the brake drum i2 and Web roll ID.

The outer ends of the levers I5 and i6 are interconnected by means of an adjustable toggle comprising turnbuckle 22 and lever 23, the lever 23 being provided with two pivots 24 and 25. Pivot 24 is connected to the outer end of lever arm I5, while the other pivot 25 receives the hook end of the turnbuckle 22, the other end of the turnbuckle being pivotally connected at 25 to lever I16. Rocking movement of the lever 23 thus serves to press the brake shoes l3 and I4 against the brake drum [2 with varying degrees of force depending upon the force applied to the upper end of lever 23.

Means are provided for automatically controlling the force applied to the brake lever 23 in accordance with the tension of the web drawn from the web roll it so as to maintain the tension substantially constant whether the roll is full or nearly exhausted, and regardless of the running speed of the web. For this purpose the web delivered from the web roll l0 passes over guide roll 30, pilot roll 3|, guide rolls 32, 33, pilot roll 34, and guide roll 35 as it is fed to the press, thus providing at least one loop in the web tending to move at least one pilot roller from its normal position against the force exerted by a weight connected to the pilot roll.

As embodied, the pilot rollers 3| and 34 are ro tatably mounted at their ends in pivoted arms 40, one such arm being provided at each end of the rollers 3| and 34 and the rollers 3| and 34 preferably being spaced substantially equal distances from the axis about which the arms 40 rotate. The arms 40 are interconnected by means of shaft 4| on which they are made fast and are supported in the side frames 42. f

Weight means are provided for opposing the movement of the pilot rollers 3| and 34 under the influence of the web tension and for this adjustably connected thereto by means of the threaded-nut 91. In order to vary the normal tension of the web fed from the web roll I U, additional weights 59 may be added to or removed from the guide rod I, thereby changing the normal tension and making it possible to establish an accurate and predetermined tension on the web.

Means are provided for controlling the predetermined normal braking force in accordance with the tension of the web as it is actually delivered from the roll. For this purpose the pilot roller supporting arms All are connected at one end to the bell crank 54 so that any increase in tension on the web beyond the desired normal tension causes the pressure on brake shoes l3 and M to be relieved sufiiciently to reduce the tension to normal. A compression Spring Bil is compressed between lug 6| on arm 40 and-a hand wheel 62 on threaded rod 63, the lower end of this rod being ,pivotally connected at 64 to the arm :65 of the bell crank 55. By means of this resilient connection between the arms carrying the pilot rollers and the bell crank 55, any counterclockwise pivotal movement of the arms 40 causes a substantially equal movement of the bell crank 55, the compression spring 50 serving to prevent the transmission of minor, rapid movements of the arms 4!! to the bell crank, :while the weights 5B and 59 serve to oppose counterclockwise movement of the arms All and also apply a normalpressure to the brake shoes I3 and 54.

In order to maintain the same tension on the web as the roll starts its rotation, on starting vup the press, as is to be maintained on the web when running at normal speeds, spring means are provided which are normally inactive but come into operation on acceleration of the web such as occurs in starting up the press. This acceleration causes a counterclockwise rotation of the pilot roller supporting arms it, and any excessive movement of the arms 4%} raises the weight guide rod 5| sufliciently to compress the spring between the guide 52 and collar H fixed to the end of rod 5|, thereby increasing the force acting on the bell crank 5 and tending to restore it to its normal running position, thereby substantially preventing a complete release of the braking force applied by the shoes i3 and I4 against the web roll.

In order to permit extremely rapid changes in the braking force applied to the web roll in weights areresiliently mounted on the guide rod 5|, so that the guide rod may move rapidly without a corresponding movement of the weights.

Any sudden movement of the bell crank 5:3 re- .sults only in a gradual change in the position of the Weights and does not cause any undue force pressed by the weights even to two-thirds or half its original length, and thus permits rapid movement of the rod 5| with only a slow, gradual movement of the weights 5t and 59. Thus rapid variation in tension such as might result from irregularities or other imperfections in the web roll as the web roll nears exhaustion do not cause a corresponding movement of the weights and the weights assume and remain in a substantially constant position. In case the pilot roller assembly suddenly moves from a condition of increasing tension to one of decreasing tension, there is no excessive increased application of the brake, as might result if the weights were not resiliently mounted.

In order to vary the effect of spring 83 in supporting the weights 59 and 59, while avoiding the necessity of changing the spring 83, a second spring 36 is provided, coiled about rod 5| and compressed between the upper end of sleeve BB and a collar 8'? adjustably secured by set screw 88. By increasing the compression of spring 86,

the weights 59 follow the movement of rod 5| more closely and give a less resilient connection between the weights and the brake.

In accordance with the modified embodiment of the invention as shown in Figures 2, 3 and 4 of the accompanying drawings, means are provided for a1lowing a fractional width web -.to be controlled as it is fed to the press, such fractional width webs usually bein one-quarter, one-half or three-quarters the width of a normal web. As

embodied the web roll is supported and braked in accordance with the construction shown in Figure 1, and the spring supported weighted means are likewise in accordance with the construction shown in Figure 1. Pilot rollers 3| .and 34 over which the web is guided as it is drawn from the web roll In to the press, are mounted in the ends of the pilot roller supporting arms til which are free to turn with reference to their supporting shaft ii. At each end, the rollers 3| and 34 are rotationally mounted in bearing blocks which are swivelled in lugs 9| formed at the ends of the supporting arms 40, this swivelling being accomplished by means of the pivot shafts 82 extending at right angles to the shaft 4| and being fixed to the bearing blocks 90 passed through suitable apertures in the lugs 9| and retained in position by means of the rollers 93. Supporting arms Ml are capable of independent rotational movement with respect to the shaft 4|, and the rollers 3i and may be parallel to each other or if one of the supporting arms at moves to a greater extent than the other, the rollers 3| and 3d assume a skew position.

Means are provided for normally maintaining the pilot rollers 3| and 35 parallel to each other while permitting them to move at either end to a larger extent than at the other end. For this purpose bell crank 54 is provided with .an outwardly extending arm 65 on which is supported an upwardly extending guide rod 63 passing upwardly through the lug 6| formed on supporting arm 40. Rod 63' is threaded to receive a hand wheel 62 on its lower portion and a hand wheel 98 on its upward portion, springs 60 and 99 being compressed by these hand wheels against the lug 6|. By varying the position of the hand wheels 62 and 93, the resiliency of the springs 60 and 99 may be controlled, lug 6| always tending to remain centrally located between the hand wheels but subject to any force applied to move the supporting arm 40.

At the far side of the tension controlling mechanism, and as shown in Figure l, a lever 100 is provided fixed to shaft fil and supporting a similar rod 63' which extends upwardly through lug 6| on the other independently .moveable pilot roller supporting arm 48'. As previously described, other hand Wheels 62 and 98, and compression springs 69 and 99 are provided between the lever [99 and this pilot roller supporting arm 49' so as to control the position of the pilot roller supporting arm with reference to the shaft 4|.

When a fractional width web is to be run, and located near one end of the web tension mechanism, the hand wheels 62 and 98 at that end are adjusted so as to allow a normal amount of resiliency in the springs iii! and 99 at that end, while the hand wheels 62 and 93 at the other end are tightened so as to reduce the resiliency of these springs and tend to hold the pilot roller supporting arm 4i) in a fixed position at that end with reference to the shaft ll. In other words, when running a quarter width web roll at the side adjacent the bell crank 54, the hand wheels 62 and 98 adjacent the quarter width web would be loosened to provide relatively great resiliency in the springs '69 and 99, while the distant hand wheels 62 and 93 cooperating with the lever lllll would be tightened so as to permit substantially no movement of the pilot roller supporting arm 40' with reference to the shaft 4|.

As described in connection with the embodiment shown in Figure 1, any movement of the shaft 4| is transmitted to the brake through the rod 95, and reacts mutually with the weights 5!) and 59 through the flexible connection 55.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. Web tensioning apparatus for applying tension to the web drawn from a web roll including in combination a web roll support, brake means for variably opposing rotation of the web roll, a pilot roller to be moved by changes in the tension of the web drawn from the roll, means for controlling the braking means in accordance with the position of the pilot roller 50 that a reduction in tension of the web increases the force with which the brake means is applied and vice versa, a weight maintaining the pilot roller in a normal position against the tension of the web and means interconnecting the weight and pilot roller including guide means on which the weight is movable and spring means to oppose movement of the weight on said guide means in either direction away from an intermediate and normal position, whereby sudden movements of the pilot roller in either direction may take place without corresponding movements of the weight, said weight being connected normally to oppose movement of the pilot roller by tension of the web.

2'. Web tensioning apparatus as claimed in claim 1 in which the weight is connected to a vertically movable guide rod through a supporting spring.

3. Web tensioning apparatus as claimed in claim 1 in which a spring separate from the spring means opposing movement of the weight connects the pilot roller to the brake for actuation of the brake.

4. Web tensioning apparatus as claimed in claim 1 in which the pilot roller is mounted for movement on a pivoted member, a spring connects the second pivoted member to the first pivoted member for movement thereby, said pivoted member forming part of the controlling means and spring means connecting the second pivoted member to the brake for controlling th brake means, said spring means connecting the weight to the second pivoted member for energization of the brake by the weight.

5. Web tensioning apparatus for applying tension to the web drawn from a web roll including in combination a web roll support, brake means for variably opposing rotation of the web roll, a pilot roller to be moved by changes in the tension of the web drawn from the roll, means for controlling the braking means in accordance with the position of the pilot roller so that a reduction in tension of the web increases the force with which the brake means is applied and vice versa, including pivoted arms in which the pilot roller is mounted for movement by the tension of the web, a lever pivotally mounted and connected to be moved by the pilot roller supporting arms and to vary the braking force of the brake means, a weight to move the pivoted lever to energize the brake and spring means resiliently connecting the weight to the pivoted lever.

6. Web tension apparatus as claimed in claim 5 in which the pivoted lever and pivoted arms are coaxial.

'7. Web tension apparatus as claimed in claim 6 in which the pivoted lever and arms are resilient- 1y interconnected.

8. Web tension apparatus for applying tension to theweb drawn from a web roll including in combination a web roll support, brake means for variably opposing rotation of the web roll, a pilot roller to be moved by changes in the tension of the web drawn from the roll, a weight, resilient means connecting the weight to the brake means for energizing the brake and permitting the brake means to be rapidly varied without substantial movement of the weight, and means for varying the braking force by movement of the pilot roller.

9. Web tension apparatus according to claim 8 in which means are provided for adjusting the resiliency of the resilient connecting means.

10. In a web tension controlling device, a pivotally movable member to be connected to actuate a web roll braking means, a pair of independently movable arms, a pilot roller journalled in said arms, said arms being coaxially pivoted with respect to said member, and separate spring means connecting each of said arms with said member for moving said member by movement of the roller, while permitting the roller to move into or out of parallelism with the pivotal axis of said member.

11. A web tension controlling device as claimed in claim 10 in which each spring means comprises a pair of alined coil springs mounted on the member and connected between them to an arm.

12. A web tension controlling device as claimed in claim 11 in which means are provided. for variably compressing the springs.

KENNETH G. LAYCOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

